Prospective Six-Month Analysis of Multiarea Burst Spinal Cord Stimulation: Correlating Intraoperative Neuromonitoring With Postoperative Programming and Clinical Outcomes.

INTRODUCTION: DeRidder burst spinal cord stimulation (SCS) has shown superior relief from overall pain to traditional tonic neurostimulation therapies and a reduction in back and leg pain. However, nearly 80% of patients have two or more noncontiguous pain areas. This affects the ability to effectively program stimulation and deliver long-term efficacy of the therapy. Multiple DeRidder burst region programming is an option to treat multisite pain by interleaving stimulation at multiple areas along the spinal cord. Previous intraoperative neuromonitoring studies have shown that DeRidder burst stimulation provides broader myotomal coverage at a lower recruitment threshold. The goal of this study is to correlate intraoperative electromyogram (EMG) threshold and postsynaptic excitability with postoperative paresthesia thresholds and optimal burst stimulation programming. MATERIALS AND METHODS: Neuromonitoring was performed during permanent implant of SCS leads in ten patients diagnosed with chronic intractable back and/or leg pain. Each patient underwent the surgical placement of a Penta Paddle electrode through laminectomy at the T8-T11 spinal levels. Subdermal electrode needles were placed into lower extremity muscle groups, in addition to the rectus abdominis muscles, for EMG recording. Evoked responses were compared across multiple trials of burst stimulation in which the number of independent burst areas was varied. After intraoperative data collection, all patients were programmed with single- and multiarea DeRidder burst. Intermittent dosing was delivered at 30:90, 120:360, 120:720, and 120:1440 (seconds ON/OFF) intervals. Numerical rating scale (NRS) and Patient Global Impression of Change scores were evaluated at one, two, three, four, and six months after permanent implant. RESULTS: The thresholds for EMG recruitment after DeRidder burst differed across all patients owing to anatomical and physiological variations. After a 30-second dose of stimulation, the average decrease in thresholds was 1.25 mA for two-area and 0.9 mA for four-area DeRidder burst. Furthermore, a 30-second dose of multisite DeRidder burst produced a 0.25 mA reduction in the postoperative paresthesia thresholds. Across all patients, the baseline NRS score was 6.5 ± 0.5, and the NRS score after single or multiarea DeRidder burst therapy was 2.87 ± 1.50. Eight of ten patients reported a ≥50% decrease in their pain scores through the six-month follow-up visit. Pain outcomes using intermittent multiarea stimulation with longer OFF times (120:360, 120:720, 120:1440) were comparable to those using single-area DeRidder burst at 30:90 up to six months after implant with patient preference being two-area DeRidder burst. CONCLUSIONS: This study aims to evaluate the use of intraoperative neuromonitoring to optimize stimulation programming for multisite pain and correlate it with postoperative programming and efficacy. These results suggest that multisite programming can be used to further customize DeRidder burst stimulation to each individual patient and improve outcomes and quality of life for patients receiving SCS therapy for multisite pain.

The Neurostimulation Appropriateness Consensus Committee (NACC)®: Recommendations for the Mitigation of Complications of Neurostimulation.

INTRODUCTION: The International Neuromodulation Society convened a multispecialty group of physicians based on expertise and international representation to establish evidence-based guidance on the mitigation of neuromodulation complications. This Neurostimulation Appropriateness Consensus Committee (NACC)® project intends to update evidence-based guidance and offer expert opinion that will improve efficacy and safety. MATERIALS AND METHODS: Authors were chosen on the basis of their clinical expertise, familiarity with the peer-reviewed literature, research productivity, and contributions to the neuromodulation literature. Section leaders supervised literature searches of MEDLINE, BioMed Central, Current Contents Connect, Embase, International Pharmaceutical Abstracts, Web of Science, Google Scholar, and PubMed from 2017 (when NACC last published guidelines) to October 2023. Identified studies were graded using the United States Preventive Services Task Force criteria for evidence and certainty of net benefit. Recommendations are based on the strength of evidence or consensus when evidence was scant. RESULTS: The NACC examined the published literature and established evidence- and consensus-based recommendations to guide best practices. Additional guidance will occur as new evidence is developed in future iterations of this process. CONCLUSIONS: The NACC recommends best practices regarding the mitigation of complications associated with neurostimulation to improve safety and efficacy. The evidence- and consensus-based recommendations should be used as a guide to assist decision-making when clinically appropriate.

Core patient-reported outcome measures for chronic pain patients treated with spinal cord stimulation or dorsal root ganglia stimulation.

BACKGROUND: Neurostimulation is a highly effective therapy for the treatment of chronic Intractable pain, however, due to the complexity of pain, measuring a subject's long-term response to the therapy remains difficult. Frequent measurement of patient-reported outcomes (PROs) to reflect multiple aspects of subjects' pain is a crucial step in determining therapy outcomes. However, collecting full-length PROs is burdensome for both patients and clinicians. The objective of this work is to identify the reduced set of questions from multiple validated PROs that can accurately characterize chronic pain patients' responses to neurostimulation therapies. METHODS: Validated PROs were used to capture pain, physical function and disability, as well as psychometric, satisfaction, and global health metrics. PROs were collected from 509 patients implanted with Spinal Cord Stimulation (SCS) or Dorsal Root Ganglia (DRG) neurostimulators enrolled in the prospective, international, post-market REALITY study (NCT03876054, Registration Date: March 15, 2019). A combination of linear regression, Pearson's correlation, and factor analysis were used to eliminate highly correlated questions and find the minimal meaningful set of questions within the predefined domains of each scale. RESULTS: The shortened versions of the questionnaires presented almost identical accuracy for classifying the therapy outcomes as compared to the validated full-length versions. In addition, principal component analysis was performed on all the PROs and showed a robust clustering of pain intensity, psychological factors, physical function, and sleep across multiple PROs. A selected set of questions captured from multiple PROs can provide adequate information for measuring neurostimulation therapy outcomes. CONCLUSIONS: PROs are important subjective measures to evaluate the physiological and psychological aspects of pain. However, these measures are cumbersome to collect. These shorter and more targeted PROs could result in better patient engagement, and enhanced and more frequent data collection processes for digital health platforms that minimize patient burden while increasing therapeutic benefits for chronic pain patients.

Interventional Pain Physician Burnout During the COVID-19 Pandemic: A Survey from the American Society of Pain and Neuroscience.

PURPOSE OF REVIEW: The study sought to assess the prevalence of physician burnout among interventional pain physicians in 2022. RECENT FINDINGS: Physician burnout is major psychosocial and occupational health issue. Prior to the coronavirus disease of 2019 (COVID-19) pandemic, over 60% of physicians reported emotional exhaustion and burnout. Physician burnout was reported to become more prevalent in multiple medical specialties during the COVID-19 pandemic. An 18-question survey was distributed electronically to all ASPN members (n = 7809) in the summer of 2022 to assess demographics, burnout characteristics (e.g., Have you felt burned out due to COVID?), and strategies to cope with burnout and stress (e.g., reached out for mental health assistance). Members were able to complete the survey once and were unable to make changes to their responses once submitted. Descriptive statistics were used to assess the prevalence and severity of physician burnout within the ASPN community. Chi-square tests were used to examine differences in burnout by provider characteristics (age, gender, years practicing, and practice type) with p-values less than 0.05 indicating statistical significance. There were 7809 ASPN members that received the survey email, 164 of those members completed the survey, a response rate of 2.1%. The majority of respondents were male (74.1%, n = 120), 94% were attending physicians (n = 152), and 26% (n = 43) have been in practice for twenty years or longer. Most respondents expressed having experienced burnout during the COVID pandemic (73.5%, n = 119), 21.6% of the sample reported reduced hours and responsibilities during the pandemic, and 6.2% of surveyed physicians quit or retired due to burnout. Nearly half of responders reported negative impacts to their family and social lives as well as personal physical and mental health. A variety of negative (e.g., changes in diet, smoking/vaping) and positive coping strategies (e.g., exercise and training, spiritual enrichment) were employed in response to stress and burnout; 33.5% felt they should or had reached out for mental health assistance and suicidal ideations were expressed in 6.2% due to burnout. A high percentage of interventional pain physicians continue to experience mental symptoms that may lead to risk for significant issues going forward. Our findings should be interpreted with caution based on the low response rate. Evaluation of burnout should be incorporated into annual assessments given issues of survey fatigue and low survey response rates. Interventions and strategies to address burnout are warranted.

Regional Coverage Differences With Single- and Multi-Area Burst Spinal Cord Stimulation for Treatment of Chronic Pain.

INTRODUCTION: Burst spinal cord stimulation (SCS) has shown superior relief from overall pain and a reduction in back and leg pain compared with traditional tonic neurostimulation therapies. However, nearly 80% of patients have two or more noncontiguous pain areas. This can provide challenges in effectively programming stimulation and long-term therapy efficacy. Multiarea DeRidder Burst programming is a new option to treat multisite pain by delivering stimulation to multiple areas along the spinal cord. This study aimed to identify the effect of intraburst frequency, multiarea stimulation, and location of DeRidder Burst on the evoked electromyography (EMG) responses. MATERIALS AND METHODS: Neuromonitoring was performed during permanent implant of SCS leads in nine patients diagnosed with chronic intractable back and/or leg pain. Each patient underwent the surgical placement of a Penta Paddle electrode via laminectomy at the T8-T10 spinal levels. Subdermal electrode needles were placed into lower extremity muscle groups, in addition to the rectus abdominis muscles, for EMG recording. Evoked responses were compared across multiple trials of burst stimulation in which the number of independent burst areas were varied. RESULTS: The thresholds for EMG recruitment with DeRidder Burst differed across patients owing to anatomic and physiological variations. The average threshold to evoke a bilateral EMG response using single site DeRidder Burst was 3.2 mA. Multisite DeRidder Burst stimulation on up to four stimulation programs evoked a bilateral EMG response at a threshold of 2.5 mA (∼23% lower threshold). DeRidder Burst stimulation across four electrode pairs resulted in more proximal recruitment (vastus medialis and tibialis anterior) than did stimulation across two pairs. It also resulted in more focal coverage of areas across multiple sites. CONCLUSIONS: Across all patients, multisite DeRidder Burst provided broader myotomal coverage than did traditional DeRidder Burst. Multisite DeRidder Burst stimulation provided focal recruitment and differential control of noncontiguous distal myotomes. Energy requirements were also lower when multisite DeRidder Burst was used.

Clinical Longevity of 106,462 Rechargeable and Primary Cell Spinal Cord Stimulators: Real World Study in the Medicare Population.

INTRODUCTION: Spinal cord stimulators (SCS) are available with either primary cell (PC) or rechargeable cell (RC) batteries. Although RC systems are proposed to have a battery longevity upward of nine years, in comparison with four years for PC systems, there are few studies of longevity of SCS in the real world. MATERIALS AND METHODS: This was an observational, nonrandomized, retrospective study of Medicare beneficiaries who received neurostimulator implants in the outpatient hospital. This study used Medicare fee-for-service claims data from 2013 to 2020. The clinical longevity of the implantable pulse generator (IPG), defined as the duration from implant until removal for any reason, was compared between PC and RC devices. Life distribution analysis was used to approximate device lifespan. The secondary analysis separated removals into explant or replacements. The statistics were adjusted for relevant clinical covariates. RESULTS: A total of 25,856 PC and 79,606 RC systems were included in the study. At seven years after implant, 53.8% of PC IPGs and 55.0% of RC IPGs remained in use. The life distribution modeling analysis projected a median lifespan of 8.2 years for PC and 9.0 years for RC devices. The rate of explant was lower for PC devices (19.2%) than for RC devices (22.0%, hazard ratio (HR) = 0.96, p = 0.082), whereas the rate of replacements was higher for PC devices (33.7%) than for RC devices (29.5%, HR = 1.31, p < 0.001). An analysis of the battery type used in device replacements showed an increasing adoption of PC devices over time. CONCLUSIONS: This large, retrospective, real-world analysis of Medicare claims data demonstrated that the clinical longevity of neurostimulator devices is similar for PC and RC batteries. In the past, clinicians may have defaulted to RC devices based on the assumption that they provided extended battery life. Considering this longevity data, clinicians should now consider the choice between PC and RC devices based on other individual factors pertinent to the patient experience and not on purported longevity claims.

Treatment of Refractory Low Back Pain Using Passive Recharge Burst in Patients Without Options for Corrective Surgery: Findings and Results From the DISTINCT Study, a Prospective Randomized Multicenter Controlled Trial.

OBJECTIVE: Spinal cord stimulation (SCS) is effective for relieving chronic intractable pain conditions. The Dorsal spInal cord STImulatioN vs mediCal management for the Treatment of low back pain study evaluates the effectiveness of SCS compared with conventional medical management (CMM) in the treatment of chronic low back pain in patients who had not undergone and were not candidates for lumbar spine surgery. METHODS AND MATERIALS: Patients were randomized to passive recharge burst therapy (n = 162) or CMM (n = 107). They reported severe pain and disability for more than a decade and had failed a multitude of therapies. Common diagnoses included degenerative disc disease, spondylosis, stenosis, and scoliosis-yet not to a degree amenable to surgery. The six-month primary end point compared responder rates, defined by a 50% reduction in pain. Hierarchical analyses of seven secondary end points were performed in the following order: composite responder rate (numerical rating scale [NRS] or Oswestry Disability Index [ODI]), NRS, ODI, Pain Catastrophizing Scale responder rate, Patient Global Impression of Change (PGIC) responder rate, and Patient-Reported Outcome Measure Information System-29 in pain interference and physical function. RESULTS: Intention-to-treat analysis showed a significant difference in pain responders on NRS between SCS (72.6%) and CMM (7.1%) arms (p < 0.0001). Of note, 85.2% of those who received six months of therapy responded on NRS compared with 6.2% of those with CMM (p < 0.0001). All secondary end points indicated the superiority of burst therapy over CMM. A composite measure on function or pain relief showed 91% of subjects with SCS improved, compared with 16% of subjects with CMM. A substantial improvement of 30 points was observed on ODI compared with a

A Prospective Multicenter Case Series Utilizing Intraoperative Neuromonitoring With Evoked Compound Action Potentials to Confirm Spinal Cord Stimulation Lead Placement.

OBJECTIVES: The use of intraoperative neuromonitoring (IONM) has been adapted to address issues of safety and proper lead positioning in spinal cord stimulation. This multicenter case series seeks to incorporate the use of evoked compound action potential (ECAP) and late response (LR) recording and compare it with the results obtained with IONM, specifically electromyography (EMG), for the confirmation of lead placement. This study aimed to establish a correlation between ECAPs, LR, and EMG and publish human recordings of ECAPs and LR during their use with IONM. MATERIALS AND METHODS: Standard neuromonitoring protocols were followed at two institutions, with two separate physicians and with seven patients, as part of a larger ongoing study registered with ClinicalTrials.gov (NCT02924129). Stimulation and recording were performed, top and bottom, on each percutaneous lead. Stimulation amplitude was increased considering ECAP, LR, and EMG thresholds. RESULTS: ECAPs, LRs, and EMG signals were observed in all patients. The onset of LR signals on implanted electrodes and EMG signal on subdermal electrodes was well correlated (rs = 0.94, p < 0.001), with a median LR:EMG value of 1.06 (N = 21). LR:EMG for the top (mean = 0.97, N = 8) vs bottom (mean = 1.15, N = 13) of the lead was compared using a paired Wilcoxon signed rank test and an independent samples Mann-Whitney test, revealing a marginally significant and a statistically significant difference (p = 0.078 and p = 0.015, respectively). Mean LR:ECAP was >2 in all locations and approximately 3.5 overall. LR:ECAP between the top and bottom of the lead was significantly different (Wilcoxon test, p < 0.01, N = 12). CONCLUSIONS: LR correlated with EMG; leads with bilateral (not necessarily symmetric) EMG activity showed LR:ECAP > 1.5. An LR:ECAP of <1, with LR/EMG generated before the ECAP, indicated that the lead is too lateral. The use of ECAP and LR has the potential of maintaining objective lead placement, without the need for needle placement with IONM.

Ultra-Low Energy Cycled Burst Spinal Cord Stimulation Yields Robust Outcomes in Pain, Function, and Affective Domains: A Subanalysis From Two Prospective, Multicenter, International Clinical Trials.

INTRODUCTION: DeRidder's burst stimulation design has become a key spinal cord stimulation (SCS) waveform because it reduces the intensity of pain as well as its associated emotional distress. The brain pathways underlying these outcomes may also allow for the effects of stimulation to carry over after stimulation is turned off, making it amenable to intermittent application. Here, the utility of intermittently cycled burst was evaluated using data from two large real-world prospective studies (TRIUMPH, REALITY). MATERIALS AND METHODS: Subjects used intermittent dosing in a 1:3 ratio (30 sec on, 90 sec off; N = 100) in TRIUMPH and 1:12 ratio in REALITY (30-sec on, 360-sec off; N = 95) for six months. Pain intensity (0-10 numeric rating scale), pain-related emotions on the pain catastrophizing scale (PCS), and physical function on PROMIS questionnaires were compared with preimplant baseline ratings and by group. RESULTS: In both groups, mean pain intensity decreased by nearly 50% relative to baseline, PCS scores significantly decreased, and physical function improved. Importantly, no differences between the 1:3 and 1:12 groups were identified. A high proportion, 80% and 77% of the 1:3 and 1:12 groups, respectively, were considered responders on a multiple measures. No adverse events were associated with intermittent stimulation. DISCUSSION: Intermittent cycling of burst SCS lowers the overall electric charge delivered to the spinal cord and preserves battery consumption, without compromising pain relief and associated symptoms.

Neuromodulation in Treating Pelvic Pain.

PURPOSE OF REVIEW: Chronic pelvic pain (CPP) is a complex condition that can be multifactorial, disabling, and difficult to treat. It is important to understand the various diagnoses and pathways that can be involved and have an understanding of the available treatment options. RECENT FINDINGS: There is a complex innervation of the pelvic region which makes its treatment very challenging. There are pathophysiological similarities of CPP to disease states like complex regional pain syndrome and sympathetically driven pain. CPP is poorly understood and includes psychological, psychosocial, cultural, and economic influences. Treatment options vary, but neuromodulation does remain a centerpiece and can include sacral stimulation, SCS, DRG stimulation, and PNS.

A Prospective Analysis of the Use of Intraoperative Neuromonitoring for Mapping the S1 Dorsal Root Ganglion Location to Determine Ideal Lead Positioning and Predict Postoperative Programming.

INTRODUCTION: The location of the sacral dorsal root ganglion (DRG) is variable and can range from a location in the canal to the foramen. It is therefore imperative to not only ensure a dorsal placement but also map the location of the DRG. MATERIALS AND METHODS: This is a prospective analysis of the use of intraoperative neuromonitoring (IONM) being utilized in asleep patients to map the location of the S1 DRG with somatosensory evoked potential (SSEP) and electromyogram (EMG) thresholds, as well as comparing this with postoperative programming. These observations were then correlated with the position of the electrode contacts relative to the sacral border. It was performed in a single center with 12 lead placements in eight patients. RESULTS: The IONM demonstrated that EMG thresholds decrease or stay the same as you stimulate more distal on the lead. Sensory signals are generated the majority of the time either proximal or on the sacral border. Postoperative programming correlated with the mapped location of the DRG on IONM, which was either posterior or on the sacral border. There was a single lead in which the IONM confirmed DRG location on the distal contact, which was anterior to the sacral border, and also correlated with postoperative programming. CONCLUSIONS: This prospective analysis further demonstrates the utility and accuracy of IONM. The use of DRG IONM is reliable for confirming dorsal placement along the S1 DRG, mapping its position, and guiding postoperative programming. The S1 DRG is located at the border of the foramen and canal in most, but not all cases.

Multicenter Retrospective Analysis of Dorsal Root Ganglion Stimulator Placement Using Intraoperative Neuromonitoring in Asleep Patients During Early Periods of Adoption.

OBJECTIVES: Intraoperative neuromonitoring (IONM) has been used in the implantation of spinal cord stimulation for both safety and confirmation of lead placement. It is less well defined in its use for dorsal root ganglion (DRG) stimulator placement. MATERIALS AND METHODS: This is a retrospective analysis of 304 leads placed in 93 patients undergoing DRG stimulation therapy with its placement utilizing IONM in asleep patients by four implanting physicians in four separate centers. The first year, or early adoption period, of placements for each site was chosen as the included cases to evaluate. RESULTS: There were a total of 14 IONM alerts across the 304 lead placements. There were two complications, no permanent or severe adverse events, and no revisions. All alerts led to a change in approach as a corrective action. The two complications were a patient requiring a blood patch for an undetected CSF leak, while the other was a generator site seroma that resolved with conservative care. A single patient experienced transient calf paresthesia's in the post-operative period. CONCLUSION: This retrospective series demonstrates the utility and accuracy of IONM in not only confirming proper dorsal placement of a DRG electrode but also in maintaining a low adverse event profile. It further demonstrates that its utility in the real world with new users can be safe and accurate with an ease of integration.

Improved Psychosocial and Functional Outcomes and Reduced Opioid Usage Following Burst Spinal Cord Stimulation.

OBJECTIVE: Burst spinal cord stimulation (B-SCS) has been shown to reduce neuronal firing in the anterior cingulate cortex through selective modulation of the medial pain pathway tract. This pain pathway communicates the affective component of pain processing. The purpose of this study was to assess the effect of B-SCS on psychosocial functioning and its influence on pain and quality of life. MATERIALS AND METHODS: Eligible patients with chronic, intractable pain of the trunk, and/or lower limbs were enrolled. After a successful trial period, subjects received a permanent implant and returned for follow-up at 6- and 12-months. RESULTS: In total, 269 patients were enrolled at 22 centers. Trial success rate was 90%. Significant improvements in pain, physical, mental, and emotional functioning were observed from baseline to the 6- and 12-month follow-up (p < 0.001). Overall, patients had improved quality of life, became more active, and the negative impact of pain on daily life was decreasing. At one year, 81% of subjects were satisfied or very satisfied with their therapy. Subjects showing significant improvements on mental health outcomes reported enhanced pain relief and quality of life scores compared with subjects with continued impaired mental health at follow-up. At one year, 89% of subjects who were taking opioids at baseline decreased or stayed at the same level of opioid use; 19% stopped taking any opioids. No unanticipated adverse events have been reported. CONCLUSIONS: One-year outcomes after B-SCS show improvements across all evaluated psychological measures with the largest impact observed on catastrophizing and depression (the affective component of pain processing). These pain-related beliefs and behaviors, and not pain intensity, have been shown to put patients at greatest risk of a poor prognosis and quality of life.

Long-Term Efficacy of a Novel Spinal Cord Stimulation Clinical Workflow Using Kilohertz Stimulation: Twelve-Month Results From the Vectors Study.

BACKGROUND AND OBJECTIVES: Multiple variables play a role in spinal cord stimulation (SCS) treatment outcomes, including patient anatomy, pain pattern, lead location, stimulation parameters, and so on. A wide range of stimulation parameters are considered safe and on-label, and as a result a growing number of new frequencies and frequency-combinations are being incorporated into standard practice. A standardized approach to therapy delivery may provide more consistent outcomes for more patients. The Vectors study evaluated whether there is significant sustained improvement in pain and functional outcomes when therapy is delivered using a standardized approach. MATERIALS AND METHODS: Vectors, a post-market, single-arm study evaluated the safety and efficacy of SCS with an implantable neurostimulator starting with 1 kHz stimulation, targeting the T9-T10 disc space following paresthesia mapping. Subjects with chronic intractable low back and leg pain (visual analogue scale [VAS] ≥ 50 mm) were enrolled. The primary endpoint was change in overall pain (VAS) at the three-month visit compared to baseline. Subjects were followed through 12 months. Secondary endpoints included changes in low back and leg pain, quality of life (European Quality of Life - Five Dimensions, EQ-5D-5L), disability (Oswestry Disability Index, ODI), individual subject goals, and subject satisfaction. RESULTS: There was a significant reduction in overall pain (VAS; 45.4 mm) through the three-month visit, which was sustained through 12 months. At 12 months, 79% of subjects had ≥50% improvement in at least one pain domain (overall, lowback or leg) with 85% of subjects reporting therapy satisfaction. There was a decrease in disability and an improvement in quality of life with 70% of subjects achieving a personal activity goal by the three-month visit. CONCLUSIONS: Long-term pain relief and improvement in quality of life and function were achieved when following a standardized workflow. CLINICAL TRIAL REGISTRATION: The Clinicaltrials.gov registration number for the study is NCT03345472.

A Systematic Literature Review of Brain Neurostimulation Therapies for the Treatment of Pain.

OBJECTIVE: To conduct a systematic literature review of brain neurostimulation for pain. DESIGN: Grade the evidence for deep brain neurostimulation (DBS). METHODS: An international, interdisciplinary work group conducted a literature search for brain stimulation. Abstracts were reviewed to select studies for grading. Randomized controlled trials (RCTs) meeting inclusion/exclusion criteria were graded by two independent reviewers. General inclusion criteria were prospective trials (RCTs and observational) that were not part of a larger or previously reported group. Excluded studies were retrospective or existed only as abstracts. Studies were graded using the modified Interventional Pain Management Techniques-Quality Appraisal of Reliability and Risk of Bias Assessment, the Cochrane Collaborations Risk of Bias assessment, and the United States Preventative Services Task Force level-of-evidence criteria. RESULTS: Two high-quality RCTs and three observational trials supported DBS, resulting in Level II (moderate) evidence. CONCLUSION: Moderate evidence supports DBS to treat chronic pain. Additional Level I RCTs are needed to further the strength of the evidence in this important area of medicine, but the current evidence suggests that DBS should be considered as an option in treating complex pain cases.

A Systematic Literature Review of Dorsal Root Ganglion Neurostimulation for the Treatment of Pain.

OBJECTIVE: To conduct a systematic literature review of dorsal root ganglion (DRG) stimulation for pain. DESIGN: Grade the evidence for DRG stimulation. METHODS: An international, interdisciplinary work group conducted a literature search for DRG stimulation. Abstracts were reviewed to select studies for grading. General inclusion criteria were prospective trials (randomized controlled trials and observational studies) that were not part of a larger or previously reported group. Excluded studies were retrospective, too small, or existed only as abstracts. Studies were graded using the modified Interventional Pain Management Techniques-Quality Appraisal of Reliability and Risk of Bias Assessment, the Cochrane Collaborations Risk of Bias assessment, and the US Preventative Services Task Force level-of-evidence criteria. RESULTS: DRG stimulation has Level II evidence (moderate) based upon one high-quality pivotal randomized controlled trial and two lower-quality studies. CONCLUSIONS: Moderate-level evidence supports DRG stimulation for treating chronic focal neuropathic pain and complex regional pain syndrome.

A Systematic Literature Review of Spine Neurostimulation Therapies for the Treatment of Pain.

OBJECTIVE: To conduct a systematic literature review of spinal cord stimulation (SCS) for pain. DESIGN: Grade the evidence for SCS. METHODS: An international, interdisciplinary work group conducted literature searches, reviewed abstracts, and selected studies for grading. Inclusion/exclusion criteria included randomized controlled trials (RCTs) of patients with intractable pain of greater than one year's duration. Full studies were graded by two independent reviewers. Excluded studies were retrospective, had small numbers of subjects, or existed only as abstracts. Studies were graded using the modified Interventional Pain Management Techniques-Quality Appraisal of Reliability and Risk of Bias Assessment, the Cochrane Collaborations Risk of Bias assessment, and the US Preventative Services Task Force level-of-evidence criteria. RESULTS: SCS has Level 1 evidence (strong) for axial back/lumbar radiculopathy or neuralgia (five high-quality RCTs) and complex regional pain syndrome (one high-quality RCT). CONCLUSIONS: High-level evidence supports SCS for treating chronic pain and complex regional pain syndrome. For patients with failed back surgery syndrome, SCS was more effective than reoperation or medical management. New stimulation waveforms and frequencies may provide a greater likelihood of pain relief compared with conventional SCS for patients with axial back pain, with or without radicular pain.

Analysis of S1 DRG Programming to Determine Location of the DRG and Ideal Anatomic Positioning of the Electrode.

INTRODUCTION: Dorsal root ganglion (DRG) stimulation has been established as a therapy in the treatment of chronic pain. Ideal electrode placement is guided by proper identification of the location of the DRG. The location of the S1 DRG is not well delineated and can be variable making ideal location of the electrode placement difficult based on fluoroscopic imaging. METHODS: This is a retrospective analysis of postoperative programming of S1 DRG leading across two centers. There were 34 lead placements in 24 patients included in this study. Programming parameters and contacts used were evaluated based on the position of the electrode in reference to the sacral border. RESULTS: The majority of the patient programming parameters were recorded at six weeks following the implant. Most commonly, the programming used a simple continuous bipole configuration. Of the 34 leads programmed, 17 (50%) had programming on the sacral border, 14 (41%) were considered posterior, and 3 (9%) were anterior to the sacral border. CONCLUSION: This analysis of S1 DRG programming demonstrates that ideal positioning of the majority of the contacts for the electrode should be posterior and along the sacral border on fluoroscopic imaging. These findings also suggest that the S1 DRG may be located most reproducibly at the border of the intraforaminal and intracanalicular region.

Safety Analysis of Dorsal Root Ganglion Stimulation in the Treatment of Chronic Pain.

BACKGROUND: Stimulation of the dorsal root ganglion (DRG) in the treatment of chronic, intractable pain has shown excellent clinical results in multiple published studies, including a large prospective, randomized, controlled trial. Both safety and efficacy have been demonstrated utilizing this therapeutic approach for many chronic complaints. Continued assessment of neuromodulation therapies, such as DRG stimulation, are not only an important aspect of vigilant care, but are also necessary for the evaluation for safety. MATERIALS AND METHODS: Safety and complaint records for DRG and spinal cord stimulation (SCS) stimulation were obtained from the manufacturer, analyzed and compiled to further assess ongoing device safety. Complaint event data were stratified according to complain type as well as overall rates. Data from similar time periods were compared between epidural neurostimulation devices by the same manufacturer as well as rates reported in the literature. RESULTS: Overall, DRG stimulation device event rates were lower or comparable to similar epidurally placed neurostimulation devices. Rates of events varied from 0 to 1.0% for DRG stimulation (n >500+ implants) which was similar to the event rate for SCS by the same manufacturer (n >2000+ implants). In comparison, complaints and adverse events ranged from 0 to 14% for SCS in the literature. DISCUSSIONS: The current results from a large consecutive cohort obtained from manufacturer records indicates that DRG stimulation demonstrates an excellent safety profile. Reported event rates are similar to previously reported adverse event and complaint rates in the literature for this therapy. Similarly, safety events rates were lower or similar to previously reported rates for SCS, further demonstrating the comparative safety of this neuromodulation technique for chronic pain treatment.

Development of an Educational Curriculum for Spinal Cord Stimulation.

BACKGROUND: Spinal cord stimulators (SCSs) are used for treating chronic pain. The number of SCSs implanted each year is on the increase. The North American Neuromodulation Society (NANS) education committee aimed to develop a SCS curriculum as a tool to guide physicians at different training levels, based on the most recent evidence. MATERIAL AND METHODS: A multidisciplinary (anesthesiology, physical medicine, neurosurgery, and neurology), taskforce representing the education committee of the NANS met to develop a SCS curriculum following the Accreditation Council for Graduate Medical Education (ACGME) milestones. The task force used the best available evidence and knowledge to develop the curriculum. Once developed, the SCS curriculum was then approved by the NANS board. RESULTS: The task force developed a SCS training curriculum. Milestones included patient care and procedural skills, system-based practice, medical knowledge, interpersonal communication, practice based learning and professionalism. Each milestone was defined for three categories, early learner, advanced learner, and practitioner. CONCLUSION: A multidisciplinary task force of the NANS education committee developed a SCS training curriculum that defines ACGME milestones for basic learners, advanced learners, and practitioners.